Overwrite
The Overwrite Data Action removes existing records from the Target Data Extension and adds new ones during each Selection run. Unlike other Data Actions, Overwrite does not require Primary Keys. However, if Primary Keys are present, SFMC automatically removes duplicate records randomly.
Example
Assume the Target Data Extension contains the following data before running the Selection:
Customer ID | First Name | Last Name | Language | |
|---|---|---|---|---|
C-100 | Jane | Jones | English | |
C-101 | Kofi | Abimbola | Dutch | |
C-102 | Paul | Chang | English | |
C-103 | Maria | Juarez | Spanish |
Sample Selection results:
Customer ID | First Name | Last Name | Language | |
|---|---|---|---|---|
C-102 | Paul | Chang | English | |
C-104 | Marie | Benoit | French | |
C-112 | Bjorn | Svenson | Swedish | |
C-100 | Jane | Jones | English | |
C-102 | Paul | Chang | Chinese |
If there’s no Primary Key set, after running the Selection, the updated Target Data Extension will contain the following data: the data in the Target Data Extension will match the results generated.
Customer ID | First Name | Last Name | Language | |
|---|---|---|---|---|
C-102 | Paul | Chang | English | |
C-104 | Marie | Benoit | French | |
C-112 | Bjorn | Svenson | Swedish | |
C-100 | Jane | Jones | English | |
C-102 | Paul | Chang | Chinese |
If there’s a Primary Key set, after running the Selection, the updated Target Data Extension will contain the following data (with Primary Key Customer ID): the data in the Target Data Extension will be in the order of the results. When a record with a duplicate Primary Key is encountered, it will just get skipped.
Customer ID [PK] | First Name | Last Name | Language | |
|---|---|---|---|---|
C-102 | Paul | Chang | English | |
C-104 | Marie | Benoit | French | |
C-112 | Bjorn | Svenson | Swedish | |
C-100 | Jane | Jones | English |